Interpretive Summary: Improvement of seed oil content and composition is an important consideration for many crop breeding efforts. The PINA and PINB proteins, which are present in wheat kernels, interact with the oily constituents of the developing wheat kernel. In this study, we introduced and produced PINA and PINB in transgenic corn seed to assess their effects on oil content and composition. The results showed that the transgenic seeds producing PINA and PINB had significantly larger germ sizes than their non-transgenic counterparts. Germ yield increased 33.8% while total seed oil content was increased by 25.23%. This work indicates that higher oil content corn hybrids having increased food or feed value could be produced via puroindoline expression.

Technical Abstract:
Plant oil content and composition improvement is a major goal of plant breeding and biotechnology. The Puroindoline a and b (PINA and PINB) proteins together control whether wheat seeds are soft or hard textured and share a similar structure to that of plant non-specific lipid-transfer proteins. Here we transformed corn (Zea mays L.) with the wheat (Triticum aestivum L.) puroindoline genes (Pina and Pinb) to assess their effects upon seed oil content and quality. Pina and Pinb coding sequences were introduced into corn under the control of a corn Ubiquitin promoter. Three Pina/Pinb expression positive transgenic events were evaluated over two growing seasons. The results showed that Pin expression increased germ size significantly without negatively impacting seed size. Germ yield increased 33.8% while total seed oil content was increased by 25.23%. Seed oil content increases were primarily the result of increased germ size. This work indicates that higher oil content corn hybrids having increased food or feed value could be produced via puroindoline expression.